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I'm still not convinced this method of charging does anything other than simulate a damn-dirty coil.
Maybe a teepee better.....?

Dave not saying its right or would work on everything out there but blocking the fan outlet like this does react differently than a dirty coil or cardboard or slowing or partialy blocking discharge air with a board or something . When you seal the whole top like this the air moves in and out past the coil vs just slowing the air.

Here are two videos, it does work like they say it does. You cannot block a condenser as it changes the design temperature difference of the coil. Blocking the coil will show a false high sub-cooling as shown in the first video.

Ok, I'm convinced. I always had luck with the pallet wrap because when I think about it I've never had to try it on a TXV, only across a piston where subcooling didn't affect it.

Jim, will this fit Rheem Classic "long body" condensing units, like in your first video? I'm responsible for a couple hundred of them, looks like it might be a trick with having the rectangle shape and having to have the cover off to connect to the system.

Here are two videos, it does work like they say it does. You cannot block a condenser as it changes the design temperature difference of the coil. Blocking the coil will show a false high sub-cooling as shown in the first video.

I am convinced this way does work differently but will not work for everything out there and certainly not to the temp extreme they claim. When I simulated this way of blocking the fan on my Carrier it was not close enough to charge by. There may be a problem with this running on taller coils.

I was taught to block the coil and not the fan. I have forgotten the reason why but maybe someone will come along who might know what the difference is.

Originally Posted by engineerdave

I'm still not convinced this method of charging does anything other than simulate a damn-dirty coil.
Maybe a teepee better.....?

I would assume this would have the same effect as cutting the ODF out on low ambient conditions which is a common method in commercial. Your pressures would stabilize better so you would be able to charge only TXV systems. I have a condenser box folded up in the truck that i use fits perfectly over the units I work with.

I am convinced this way does work differently but will not work for everything out there and certainly not to the temp extreme they claim. When I simulated this way of blocking the fan on my Carrier it was not close enough to charge by. There may be a problem with this running on taller coils.

From what I understand it is being used in programs all over CA successfully. Russ would have to comment on that. I have only tested it down to the mid/low 50s, I agree that 37 sounds really low. I think you would run into other problems like low indoor load, and issues with A/C systems that are not equipped with low ambient protection like crank case heaters. That aside, even it it only worked well at the 50s and up it still extends the time you can work. A cheap investment for the return. It will work on square units. There are simply hooks to hold it in place.